FEAT-#2375: removed unnecessary 'drop' in '_apply_agg_function'

Signed-off-by: Dmitry Chigarev <[email protected]>

modin/backends/base/query_compiler.py

@@ -1408,13 +1408,10 @@ def groupby_agg(
         groupby_kwargs,
         drop=False,
     ):
-        if is_multi_by:
-            if isinstance(by, type(self)) and len(by.columns) == 1:
-                by = by.columns[0] if drop else by.to_pandas().squeeze()
-            elif isinstance(by, type(self)):
-                by = list(by.columns)
-        else:
-            by = by.to_pandas().squeeze() if isinstance(by, type(self)) else by
+        if isinstance(by, type(self)) and len(by.columns) == 1:
+            by = by.columns[0] if drop else by.to_pandas().squeeze()
+        elif isinstance(by, type(self)):
+            by = list(by.columns)
 
         return GroupByDefault.register(pandas.core.groupby.DataFrameGroupBy.aggregate)(
             self,

modin/data_management/functions/default_methods/groupby_default.py

@@ -75,11 +75,6 @@ def fn(
         ):
             by = cls.validate_by(by)
 
-            if not is_multi_by:
-                groupby_args = groupby_args.copy()
-                as_index = groupby_args.pop("as_index", True)
-                groupby_args["as_index"] = True
-
             grp = df.groupby(by, axis=axis, **groupby_args)
             agg_func = cls.get_func(grp, key, **kwargs)
             result = (
@@ -88,15 +83,7 @@ def fn(
                 else agg_func(grp, **agg_args)
             )
 
-            if not is_multi_by:
-                if as_index:
-                    return result
-                else:
-                    if result.index.name is None or result.index.name in result.columns:
-                        drop = False
-                    return result.reset_index(drop=not drop)
-            else:
-                return result
+            return result
 
         return fn
 

modin/pandas/groupby.py

@@ -900,15 +900,7 @@ def _apply_agg_function(self, f, drop=True, *args, **kwargs):
             f, dict
         ), "'{0}' object is not callable and not a dict".format(type(f))
 
-        # For aggregations, pandas behavior does this for the result.
-        # For other operations it does not, so we wait until there is an aggregation to
-        # actually perform this operation.
-        if not self._is_multi_by and self._idx_name is not None and drop and self._drop:
-            groupby_qc = self._query_compiler.drop(columns=[self._idx_name])
-        else:
-            groupby_qc = self._query_compiler
-
-        new_manager = groupby_qc.groupby_agg(
+        new_manager = self._query_compiler.groupby_agg(
             by=self._by,
             is_multi_by=self._is_multi_by,
             axis=self._axis,